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For a linux user, the terminal or command line is a powerful and important tool for work. A lot of things on linux are done inside the terminal. When working on a linux server, the command line shell is the only interface to work with, most of the time. But the terminal is also very textish and a bit non-interesting at time. The linux terminal is not always dull and boring. There are commands to m

Linux ps command The ps command on linux is one of the most basic commands for viewing the processes running on the system. It provides a snapshot of the current processes along with detailed information like user id, cpu usage, memory usage, command name etc. It does not display data in real time like top or htop commands. Even though it has fewer features, it is still an essential process manage

CPU hardware information The cpu information includes details about the processor, like the architecture, vendor name, model, number of cores, speed of each core etc. There are quite a few commands on linux to get those details about the cpu. In this post we shall take a look at some of the commonly used commands that can be used to get details about the cpu. 1. /proc/cpuinfo The /proc/cpuinfo fil

Raw UDP sockets Raw udp sockets are used to constructed udp packets with a application defined custom header. It is useful in security related network applications. The udp header can be found in RFC 768 and has a very simple structure as shown below. 0 7 8 15 16 23 24 31 +--------+--------+--------+--------+ | Source | Destination | | Port | Port | +--------+--------+--------+--------+ | | | | Le

scp command - Secure copy Scp (Secure Copy) is a command line tool to copy or transfer files across hosts. It uses the same kind of security mechanism like the ssh program. Infact it uses an ssh connection in the background to perform the file transfer. scp refers both to the "protocol" that defines how secure copy should work and the "program" (command) which is installed as a part of OpenSSH sui

Home > Linux > Linux Commands > 8 Examples of findmnt Command to Check Mounted File Systems on Linux Mounted file systems and devices The more common command to check mounted file systems on linux is the mount command which is used to not only list mounted devices, but also mount and unmount them as and when needed. Here is another nifty command called findmnt, that can be used to take a quick loo

Home > Linux > Server > 10 Examples of Linux ss Command – Monitor Network Connections ss - socket statistics In a previous tutorial we saw how to use the netstat command to get details about the network/socket connections. However the netstat command has long been deprecated and replaced by the ss command from the iproute suite of tools. The ss command is capable of showing details about network c

Monitor system resources System administrators need to monitor their server to ensure proper functioning. The practice enables administrators to detect possible issues in advance and recover the system, before it causes any trouble. There are plenty of commands on Linux to monitor different system resources like cpu usage, memory usage, network, disk usage and so on. Popular ones are top, htop, io

Home > Linux > Linux Commands > 10 Basic Examples of Linux Netstat command – Check Ports and Connections Netstat is a command line utility that can be used to list out all the network (socket) connections on a system. It lists out all the tcp, udp socket connections and the unix socket connections. Apart from connected sockets it can also list listening sockets that are waiting for incoming connec

Memory Usage On linux, there are commands for almost everything, because the gui might not be always available. When working on servers only shell access is available and everything has to be done from these commands. So today we shall be checking the commands that can be used to check memory usage on a linux system. Memory include RAM and swap. It is often important to check memory usage and memo

Sniffers are programs that can capture/sniff/detect network traffic packet by packet and analyse them for various reasons. Commonly used in the field of network security. Wireshark is a very common packet sniffer/protocol analyzer. Packet sniffers can be written in python too. In this article we are going to write a few very simple sniffers in python for the linux platform. Linux because, although

Home > Coding > Socket Programming > Python > Python socket programming Tutorial – How to Code Client and Server Socket programming in Python This is a quick guide/tutorial on socket programming in python. Socket programming python is very similar to C. To summarise the basics, sockets are the fundamental "things" behind any kind of network communications done by your computer. For example when yo